Piston for internal-combustion engines



1,502,923 R. L. SKINNER PISTON FOR INTERNAL COMBUSTION ENGINES OriginalF l d ay 26, 1921 2 Sheets-Sheet 1 iiiiii July 29, 1924. N

R. L. SKINNER PISTON FOR iNTERNAL COMBUSTION ENGINES Original F1106 y26, 1921 2 Sheets-Shoo! 2 l I I 1 Patented July 29, 1924.

warren STATES PATENT oFFicE.

RALPH L. SKINNER, OF DETROIT, MICHIGAN, ASSIGNOR 'IO SKINNER, AUTOMOTIVEDEVICE CO., INC., OF SACRAMENTO, CALIFORNIA, A CORPORATION OFCALIFORNIA.

PISTON FOR INTERNAL-COMBUSTION ENGINES.

Original application filed May 26, 1921, Serial No. 472,746 Divided. andthis application filed August 30, 1922. Serial No. 585,309.

To all whom it may concern:

Be it known that I, RALPH L. SKINNER, a citizen of the United States,residing at Detroit, in the county of \Vayne and State of Michigan, haveinvented certain new and useful Improvements in Pistons forInternal-Combustion Engines, of which the following is a specification.

The lubricating oil splashed or otherwise fed on to the inner walls ofthe engine cylinders of internal-combustion engines for frictionreducing purposes by the moving crankshaft and connecting rods andpossible accessories, in engines or motors of the present day, finds itsway in substantial quantities past the reciprocating pistons into thefuel combustion chambers above them, due to several causes, includingthe excess of oil on the cylinder walls, the movements of the pistons,and the sub-atmospheric pressure in such chambers during the intakestrokes of their pistons.

The oil thus present in the. chambers becomes converted intoobjectionable carbon on the piston heads, the walls of the chambers, andthe spark-plugs'bringing about the well-known undesirable effects on thesmooth and eflicient operation of the motor.

In addition, the direct contact of such lubricating oil with thespark-plugs, which is likely to occur if the pistons are somewhat loosefitting, brings about their short-circuiting hence rendering themuseless until cleaned or replaced.

Such excess of oil as enters the firing chambers represents asubstantial oil loss or needless consumption because it performs nouseful function, its presence therein constituting a menace to theproper action of the motor. 1

Also, the more or less unconsumed gaseous or liquid fuel and products ofcombustion escape downwardly past the pistons into the crank-case wherethey seriously dilute and contaminate the supply of lubricating oiltherein.

This is particularly true in winter when the fuel is not so readilyvaporized and when it is more difficult to start the engine and isalso-especially true if the pistons fit the cylinders somewhat looselbut such objectionable polluting of the Oll, thereby materially reducingits lubricating qualities, occurs to a serious extent. even in motors inthe best runnlng order, due particularly to the low grade of liquid fuelnow on the market and in common use.

0 The prime aim and salient purpose of this invention is the provisionof an improved and novel style of piston adapted for association withsimple, effective, economical and inexpensive means to prevent theupward passage of the excess oil by-the pistons into the explosionchambers and to preclude the downward flow of the fuel and combustiongases past the pistons into the crankcase.

In the use of an improved appliance of this kind including new pistons,there is a separate recovery of the excess oil and fuel, the formerbeing returned to the engine crank-case .for further use and the latterintroduced into the intake manifold of the engine for consumption in thecombustion chambers thus effecting a radical saving in both elements.

Another goal of the invention is the production of an appliance of thiskind, including the new styles of pistons, which will cf ficientlyperform the functions specified and which may be installed in new motorsat the time of manufacture or which may be readily incorporated inmotors already in service.

The use of the improved pistons in cooperation with other parts of the.mechanism will permit the use of thinner or lighter grade of lubricatingoil for the pistons of the motor than has heretofore been usual with itsadvantages of reduced friction losses but without incurring the usualdisadvantages ordinarily incident to the employment of such kind orgrade of oil.

To enable those skilled in this art to have a full and completeunderstanding of this invention both from structural and functionalstandpoints and to indicate how the above-stated and other objects ofthe invention are accomplished, I have illustrated in the accompanyingdrawings forming a part of this specification a desirable embodiment ofthe invention and like reference characters have been used to refer tothe same parts throughout the several views.

' one of the engine cylinders and its In these drawings: Y I

Figure 1 is a side elevation of an internalcombustion engine equippedwith the new style-and form of piston, although the latter are-notspecifically illustrated in this view;

Figure 2 is a plan view of the same engine;

Figure 3 is a fragmentary section through improved form of piston; and

Figure 4 is a side elevation of the p ston.

By reference to these drawings, it will be seen that the multi-cylinderinternal-combustion engine or motor of the usual form, and which mayhave any appropr ate or well-known splash or forced feed or otherlubricating system for its cylinders and pistons, has been supplied as awhole w1th the reference numeral 21, each of its four cylinders,water-jacketed or air-cooled as the case may be, as shown in Figures 2and 3, being designated 22.

Each hollow, open-ended, reciprocatory.

piston 23 at its upper portion, as is customary, has a plurality ofpiston-rings 24, 24, three being used in the present instance, and justbelow these the piston is provided with a shallow, annular groove orchannel 25 extended entirely around the piston and adapted to be insubstantial register, when the piston is atthe lowermost point in itsstroke, with a port or aperture 26 through the cylinder wall and throughwhich in a manner hereinafter explained suction or sub-atmosphericpressure is effected in the groove 'Diametrically opposite port 26, thepiston has a small air-admisson relief or bleeder port or aperture 27extended through His wall and therefore in communicatlon with theinterior of the hollow piston and with the crank-case atmosphere.

-As is usual in this art, the external diameter of the lower portion ofthe depending skirt of the piston is slightly greater than that ofthe'upper part of the piston, the latter being subject to greater rangesof temperature and to greater degrees of expansion and contraction thanthe lower section of the skirt.

It is, therefore, somewhat more essential to effectively lubricate suchskirt than the upper portion of the piston, and, heretofore, to preventexcess lubrication, its lower por tion has usually been 'itted with apistonring to wipe off the s rplus oil from the cylinder wall.

In the present device, owing tothe removal of the excess oil in anotherway, such lower ring is omitted and hence there is decreased wear on thecylinder wall.

It is desirable to subject the oil or fluid collecting groove 25 to thesuction or ex-.

hausting action through port 26 for an extended period of time for theeffective and efficient removal of its contents, and this port 26, thepiston is externally longitudinally grooved at 28, the upper end of suchchannel opening into the round or circumferential groove 25.

The piston on its longitudinally grooved side," although this is notnecessary on some pistons, has an extension 29 having an external groove30 in alignment with the companion groove 28, the former extendingupwardly slightly on to the extreme lower portion or face of the pistonskirt.

As is clearly shown in Figure 3, the middle section of the lower grooveor channel 30 is connected through a passage 31 in an internal rib 32 onthe piston skirt and its extension with the lower end of the uppergroove 28 and groove 30 is fitted with a suitably-shaped leaf spring orflap valve 33 adapted to control-the opening and closin of theconnection between such groove anil the passage 31. Such valve is heldin place by a screw 34 through one end thereof which fastens it to-thebase of the groove.

This piston skirt extension is required by reason of the fact that thepiston in its lowermost position, as'is indicated in Fgure 3, projectsbelow the bottom end of the cylinder wall. During the ascent of thepiston, so long as any part of channel 28 is opposite port 26 suctionwill be exerted on the oil collecting groove 25, and because of suchsuction action valve 33 is maintained closed, although its spring forcemay be suflicient for the performance of this function.

When the part of the piston between the lower end of channel 28 and thetop end of channel 30, during the rise of the piston, temporarily closesport 26, the suction or exhausting action on the groove encircling thepiston is for the time being omitted.

During the registration of channel 30 with the suction-port 26, theexhausting action is restored, valve 33 opening outwardly under thesuction influence so that the oil in groove 25 and any other fluids aredrawn out through channel 28, passage 31, groove 30 and port 26.

Thus an effective oil removing suction action is exerted on the annulargroove during the greater portion of the time, even though the piston israpidly reciprocatin The air-admission port or its equiva eat is highlydesirable, because if it or its equivalent is not employed, the suctionwill not remove the oil to a wholly effective and satisfactory degree.

Such air-inlet or bleeder port assures atmospheric pressure at thatpoint and hence establishes a substantial difference in air pressure atthe opposite points in the groove, this bringing about a rapid andenergetic through a heater or heat exchanger or gasidischarge flow ofthe aerated oil and other fluids around both sides of the piston ingrooves 25 and out through the cylinder port 26.

It is to be observed that by the means described a suction ring 'or zonearound the rapidly traveling piston is established and maintained justbelow its piston-rings.

Any fuel, therefore, in liquid, vapor or. gaseous form. and any heatedproducts of combustion escaping own past the piston rings come under theinfluence of this suction or exhausting action and they, with the oil,and the admitted air. are conveyed away through the port 26, all as willbe readily understood.

By this comparatively simple means an excess of lubricating oil isprevented from entering the combustion chamber above the piston anddilution or contamination of the crank-case oil is eliminated at thesame time by removing the elements which tend to pollute the oil beforethey reachthe crankcase.

The exhaust or suction ports 26 of the several motor cylinders are bysuitable means connected to a pipe or manifold 35 common to all of themand the middle portion of this is connected to a pipe 36 communicatingwith an upright pipe 37 passing fier 38, the-upper end of pipe 37 beingconneeted to the top of an oil trap or separator 39 by a pipe 40, thebottom of element 39 having a pipe connection 100 with the crankcase forthe return thereto of the oil drawn from around the pistons.

The gases, freed from oil, leave the trap orseparator through a bentpipe connection 41 which at the rear end of the motor exhaust-manifold42 communicates at 43 with a heater pipe 44 extending lengthwise throughthe interior of the manifold, whereby its gaseous contents areadequately heated by the hot exhaust gases of the motor flowing throughthe manifold around such interposed pipe.

The front end of heater-pipe 44 is connected by another pipe 45 to theheat-exchanger or gasifier 38, whereby such heated gases as flow throughthe pipe 45 may impart at least a portion of their heat to the mixtureof air, gases and oil passing upwardly through pipe 37, thus assuringadequate, but not excessive, heating of the contents of suchpipe toinsure proper volatilization of the gasifiable constituents preliminaryto their passage into the oil-separator.

From the heater or gasifier 38 the' hot gases flow through a pipeconnection 45* in to the intake manifold of the motor to be emplo ed asa part of and as a previously heate' ingredient of the explosive mixturein the running of the'motor.

This patent application constitutes a division of my eo-pending patentap lication Serial Number 472,746, Internal combustion engine oil andfuel appliance, filed May 26th, 1921, and inasmuch as the details ofconstruction of the separating tank 39 have been presented in suchcompanion application and form no part of the present invention,

further description of thesame is apparently unnecessary.

By establishing and maintaining a belt -or band around each piston of apneumatic case for further use, the gaseous mixtureheated by the exhaustof the engine, and such heated mixture used to heat the mixturecontaining the oil previous to the removal of the latter therefrom, andthen passing into the engine intake-manifold as heated fuel to serve aspart of the fuel used in running the engine.

plosion or firing chambers of the engine from the lubricating oil isprevented, and the dilution and pollution of the crank-case oil isavoided, a saving in oil and fuel bein effected at the same time.

n addition, the separated or collected oil, free from deleterious,volatile or diluent ingredients, is returned from the separator atintervals to the engine sump without destroying or modifying the fluidremoving suction on the pistons.

By means of this structure, the skirt portion of the piston of largerdiameter than the piston head and hence naturally requiring the greaterlubrication, is treated to a liberal supply of oil for friction reducingpurposes, and this is accomplished without danger of any substantialquantity of the oil reaching the firing chamber and forming carbontherein.

Thelubricating oil employed may also be lighter or thinner than isordinarily used, because under present engine conditions withoutemploying this invention the heavier oil is required to prevent too muchfrom passing by the pistons.

Engineers are attempting to preclude or avoid the passage of the severalfluids mentioned past the pistons by employing stifler and strongerpiston-rings, but their use is objectionable because of the excessivewear which they necessarily produce on the cylinder walls.

Those acquainted with this art willreadily Thus the formation of carbonin the exparture from the substance andessence of.

the invention and without the sacrifice of any of its substantialbenefits and advantages.

1 claim:

l. Aninternal-coinbustion engine piston having an external, transversechannel, an external longitudinal groove communicating with said channeland adapted when opposite a port in the engine cylinder wall toestablish connection between such port and channel, and a lengthwiseextension at one side of the piston-skirt in register with saidlongitudinal groove and adapted to co-' operate with said cylinder-port.

2. An internal-combustion engine piston having an external, transverse,fluid-collecting channel, an external, longitudinal groovecomn'iunicating with said channel and adapted when opposite a port inthe engine cylinder wall to establish connection hetweensuch port andchannel, an airinlet port communicating with said channel.

at a point remote from its connection with said groove, and a lengthwiseextension at one side of the piston-skirt in register with saidlongitudinal groove and adapted to cooperate with said cylinder-port.

3. A hollow, open-ended, internal-combustion engine-piston having anexternal, circumi'erential, fluid-collecting channel extended around it,an external, longitudinal groove communicating with said channel andadapted when opposite a port in the engine cylinder wall to establishconnection between such port and channel, an airinlet port connected tosaid channel substantially diametrically opposite said longitudinalgroove and extended inwardly through the piston wall to itshollowinterior, and a lengthwise extension at one side of the piston-skirt inregister with said longitudinal groove and adapted to cooperate withsaid cylinder-port.

4. An internal-combustion engine piston having an external, transversechannel, a. lengthwise extension at one side of its skirt, and anexternal longitudinal groove on said extension in communication withsaid channel.

5. An internal-combustion engine iston having an external, transversechanne and two external aligned spaced grooves in communication withsaid channel.

6. An internal-combustion engine piston having ail-external,transversechannel, two external aligned spaced grooves, one of which isconnected to said channel, and a passage connecting said grooves.

7. An internal-combustion engine piston having an external, transversechannel, two external aligned spaced grooves one oi which'connects withsaid channel, a passage connecting said grooves, and a valve controllingsaid passage.

.8. An internal-combustion engine piston, the skirt of. which at oneside has an extension, said piston having an external transverse channeland a pair of external aligned spaced grooves on said skirt andextension channel.

9. An internal-combustion engine piston having an external transversechannel, a lengthwise extension at one side of said skirt, an externallongitudinal groove on said extension in communication with saidchannel, and a relief port communicating with said channel.

10. An internal-combustion engine piston having an externaltransversechannel provided with a relief-port and two external alignedspaced grooves in communication .with said channel.

11. An internal-combustion engine piston having anexternal transversechannel proin communication with said vided with a relief-port, twoexternal aligned spaced grooves one of which connects with said channel,a passage connect-- ing said grooves, and a valve controlling saidpassage.

12. An internal-combustion en ine piston, the skirt of which at one sideas an extension, said piston having an external transverse channelprovided with a relief port, a pair of external aligned spaced grooveson saidskirt and extension, a passage connectin said grooves, and avalve controlling said passage.

13. An internal-combustion engine piston having one or more piston-ringgrooves and piston rings at its upper end only, an external transversechannel below said piston ring or rings, an external longitudinal groovecommunicating with said channel, and a relief-port communicating withsaid channel remote from said longitudinal groove.

14. An internal-combustion engine piston having an external transversechannel, an external longitudinal groove communicating with saidchannel, and an air relief port communicating with said channel at apoint remote from said longitudinal groove.

15. An internal-combustion en ine piston having an external transverse cannel, an external longitudinal groove communicating with said channel,and an air relief port communicating with said channel diametricallyopposite said longitudinal groove.

16. A hollow internal-combustion engine piston having an externaltransverse channel, an external longitudinal groove'communicating-withsaid channel, and an air relief port communicating with said chananexternal, circumferential, fluid-collect nel at a point remote from saidlongitudinal groove and extending inwardly through the piston wall toits hollow interior.

17. A hollow, open-ended, internal-combustion, engine-piston having oneor more piston-ring grooves at its upper end only,

ing channel below the lowermost pistonring groove, an external,longitudinal groove communicating w1th said channel and adapted whenopposite a port in the engine cylinder wall to establish connectionbetween such port and channel, an air-inlet port communicating with saidchannel at a point remote from its connection with said groove, and alengthwise extension at one side of the piston-skirt in register withsaid longitudinal groove and adapted to cooperate with saidcylinder-port.

In witness whereof I have hereunto set 20 my hand and seal.

RALPH L. SKINNER. [L. 5.]

